The combination of zirconocene-mediated coupling of silylated alkynes with a protonation−desilylation or bromination−desilylation process afforded otherwise unavailable butadiene derivatives. When (E,E)-2,3-dialkyl-1,4-bis(trimethylsilyl)-1,3-butadienes were treated with 3 equiv of Br2 in CH2Cl2, (E)-2,3-dialkyl-1,1,4,4-tetrabromo-2-butenes were obtained in excellent yields with perfect stereoselectivity
锆茂茂介导的甲
硅烷基化
炔烃的偶合与质子化-去甲
硅烷基化或
溴化-去甲
硅烷基化过程的结合提供了否则无法得到的
丁二烯衍
生物。当在CH 2 Cl 2中用3当量的Br 2处理(E,E)-2,3-二烷基-1,4-双(三甲基甲
硅烷基)-
1,3-丁二烯时,(E)-2,3-二烷基以优异的产率和完美的立体选择性获得了-1,1,4,4-四
溴-
2-丁烯。